A muffle for producing ceramic dental restoration components, as known for example from DE 10 2004 013 668 A1, usually comprises a pressing channel and at least one mold cavity that is coupled to the pressing channel via at least one connection channel, whereby the material of a press blank inserted into the pressing channel fills the mold cavity if a pressing force is applied and the press blank is heated, and thus provides a fired ceramic dental restoration component.
In practice, however, again and again cracks and even cavities arise in ceramic dental restoration components that impair the strength and the quality of the ceramic dental restoration component.
It has been proposed to form a press chamber with a particular cross-section in a muffle, whereby a blank material in the form of a bulk material can be filled into the press chamber and is pressed into a ceramic dental restoration component. In this case, however, air pockets can remain that cannot be completely eliminated by the pressure of the press stamp during the sintering process either.
The pressing force that is effective in the mold cavity according to the proposed solution, is comparatively low due to the shape of the pressing channel—probably due the the wall friction. Further, there is the danger that a press stamp guided in the pressing channel easily jams as a result of the particular cross-section.